Maybe it's because I'm a Londoner living in an overcrowded city on a tiny island where courts are in short supply, but I love seeing tennis courts: from a plane as it descends (there never seem to be any on the way up) or from speeding trains and cars. This is a purely aesthetic -- i.e., pointless -- pleasure, but if I am out walking or cycling, this fondness for court-spotting has obvious practical advantages. Over time, in London, I have discovered every public court within a playable distance of home. When I moved to Paris, wandering through my neighborhood, the 11th Arrondissement, I occasionally glimpsed courts tucked away, in a courtyard or at the end of an impasse. These discoveries were temporal as well as spatial: some days the courts were there, some days they weren't; what had been a tennis court had suddenly become a basketball court or a five-a-side pitch. These sites were marked by a tangle of different-colored lines, each designating a particular sport. I especially loved the court at Passage Thiere, which, though it existed only at odd and unpredictable times, was a mere five minutes' walk from my apartment on rue Boulle. It was just a single court surrounded on three sides by buildings -- apartment blocks with geraniums on tiny balconies and wash hanging out to dry -- which created stadiumlike acoustics when you made contact with the ball. [ABSTRACT FROM AUTHOR]